Still running into wasm debugging. I am on debug and a new project do work but not the project that I stared 8 months ago. I have deleted bin file and obj and user temp files.
<PackageReference Include="Uno.UI.WebAssembly" Version="3.2.0-dev.83" />
<PackageReference Include="Uno.UI.RemoteControl" Version="3.2.0-dev.83" Condition="'$(Configuration)'=='Debug'" />
<PackageReference Include="Uno.Wasm.Bootstrap" Version="1.5.0-dev.57" />
<PackageReference Include="Uno.Wasm.Bootstrap.DevServer" Version="1.5.0-dev.57" PrivateAssets="all" />

It's probably caused by old packages. Following instructions on this page and there should solve your problem:
Uno.UIto latest versionUno.WasmBootstrap&Uno.UI.RemoteControlto latest versionsUno.Wasm.Bootstrap.DevServer.csprojand remove any<DotNetCliToolReference />It should work after that.